Small Engines (Lawn Mowers, etc.): 5hp Briggs and Stratton IC, briggs and stratton, fuel nozzle

Question
QUESTION: I have a hp Briggs and Stratton IC and My carburetor Is one of those that sits down on top of the gas tank with valves that go into the gas in the gas tank. My problem is I am not getting any gas to the carburetor and I have put a new Diaphragm on and cleaned it but nothing happened.But if you pour gas directly to the carburetor it starts right up but dies because it burns up the gas. Do you know what my problem is?

Thanks

ANSWER: The way these carburetors work is that the long tube is a pick-up tube, the diaphragm is a fuel pump, the small tank that the short tube sits in is essentially a fuel bowl and the short tube is the fuel nozzle and picks the fuel up from the bowl and feeds it into the airstream.

So, to diagnose the problem, you have to determine where in the system the fault is.  If you remove the carburetor and the small tank or fuel bowl is empty, then you know that the problem is between the fuel pick-up and the bowl.

If the bowl is full, then you know that the problem is in the fuel nozzle.

As you have a new diaphragm, you've probably eliminated that as a cause.  Be sure that it seats well and is on properly.  Then use some carb cleaner and a fine wire and clean out all the little holes.  

If it's the fuel nozzle, it's usually just a little dirt and the wire and cleaner will get it.  If it's the pumping circuit, then it may be a little trickier, but you can probably get it clean.

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QUESTION: HI i had the 5hp briggs IC and its still not sucking up gas through carberator with valves. Any more suggestions?

Answer
If you cleaned out the carburetor really well, using wire to chase all the circuits, then I'd check for air leaks.  Spray some starting fluid around the intake where the carb mounts to the engine while trying to start it.  If the engine hits, then there's a leak that need to be fixed.  If gas is leaking into the diaphragm, you have a leak there.  The mating surfaces must be flat and clean.

You may have a carburetor that needs to be replaced.  There's a check ball in the pick-ups of most of these style carburetors.  If it's stuck, then fuel won't be pulled up by the diaphragm.  Sometimes you can free this by spraying carb cleaner into the pick-up tube.  We replace about 25% of the carburetors that come through the shop.  Sometimes it's simply more cost-effective to replace than to spend the time and money trying to get the old one to work.

If you would like a price on a replacement, send me the model, type and code number off the engine and I'll get that and the part number for you.